As is known in the art, electrode lines of this type generally have an elongate, tubular electrode body, in which a line coil with a plurality of coradially bundled coil wires is guided from a corresponding base unit, such as, for example, an implanted heart pacemaker, to the respective electrodes provided, such as, for example, a ring electrode and a head electrode.
A fundamental problem with an electrode line of this type is the strain-resistant, that is to say mechanically and electrically secure, electrical connection between the line coil and the respective electrode. Here, suitable strain-relief measures have to be provided, in particular, in order to protect the mechanical and electrical protection there between the line coil and the respective electrode against the constant dynamic loads.
Various design measures for this problem are known from the prior art. Wires or cables, which form the line coil to be contacted, thus run axially between two contact sleeves and are fixed between an inner and outer sleeve. In this case, the components can be crimped together or resistance welded or laser welded.
In accordance with another known design solution, a coil to be contacted in the composite is fitted onto an annular shoulder-shaped heel of a sleeve forming the electrode, where it is to be electrically attached and mechanically coupled by means of welding.
Conversely, it is also conventional to insert a coil to be contacted into an electrode sleeve in order to form the head or ring electrode and to mechanically and electrically attach it there by means of resistance welding or laser welding.
Lastly, it is also known to allow a cable to be contacted to run axially into a recess in an annular sleeve, where a connection can be produced by welding or crimping.
All previously known connection techniques, as are known by public prior use, have the disadvantage that, with dynamic movements, strains and tensile loads, a direct load onto the connection or onto the transition from the flexible feed line region to the rigid region to be contacted is produced. This presumes a high fatigue limit of these conventional electrical and mechanical connections. In particular, with increasingly smaller components with relatively small cross sections, the necessary level of reliability for a transfer of force and electrical contacting is often no longer met. A further problem is that the thermal methods, such as welding methods, are subject to process fluctuations and can additionally cause a mechanical weakening of the wire to be attached. For safety reasons, it has therefore previously not been possible to connect, for example, an individual coil wire to contact annular sleeves or head electrodes, wherein a sufficient transfer of tensile force is provided at the same time.
The present invention is directed toward overcoming one or more of the above-identified problems.
Proceeding from the described problems of the prior art, an object of the present invention is to create a contacting device for electrical connections to the described electrode lines, with said device providing a reliable strain relief of the electrical connection between the line coil and corresponding electrode with optimized protection against tensile load and/or other constant mechanical/dynamic loads.